<form>
  <!-- 文本输入框 -->
  <div class="form-group">
    <label>用户名：</label>
    <input type="text" name="username" class="input-field required">
  </div>

  <!-- 密码输入框 -->
  <div class="form-group">
    <label>密码：</label>
    <input type="password" name="password" class="input-field required">
  </div>

  <!-- 按钮 -->
  <button type="submit" name="submit-btn" class="btn primary">登录</button>
</form>